The victims: The death toll has risen to 359 people. Hundreds more were injured in the attacks, which targeted several churches and luxury hotels.

Second wave of attacks planned? The National Tawheed Jamath (NTJ) group has been implicated by the Sri Lankan government, but it has not claimed the bombings. A high-level intelligence official told CNN that NTJ was also planning another set of attacks.

1:23 a.m. ET, April 24, 2019

Hotel bans facial coverings, including the burqa

From CNN's Jenni Marsh and Caitlin Hu in Hong Kong

Signs at the Ella Flower Garden Resort banning people with face coverings from entry.

At least one Sri Lankan hotel has banned facial coverings in the aftermath of the attacks.

A British guest at Ella Flower Garden Resort in the small mountain town of Ella, about 200 kilometers (about 125 miles) east of Colombo, told CNN that the rule began on Tuesday, and described it as "a hijab and burqa ban."

Signs on the hotel's glass door depict a variety of banned facial coverings, including icons of a helmet, an eye mask, a balaclava, an eyeless full-figure shroud, and an apparent Islamic burqa.

The ban specifically mentions people in Islamic headdress.

Kosala Dissanayake, the hotel's director of sales, confirmed the rule, and emphasized to CNN that the ban extended to all face coverings.

"We mention on signs in here about full-face helmet and fully-covered jackets," he said. "Because of the current situation going on Sri Lanka, we have to take some tough decisions," he added.

The hotel's ban follows allegations that Muslim extremists were responsible for the coordinated attacks, which killed at least 359 people in churches and luxury hotels.

The Sri Lankan government has warned that attackers could still be at large, and several countries have issued travel warnings for the country.

12:47 a.m. ET, April 24, 2019

Sri Lankans turn to VPNs in massive numbers as social media ban continues

CNN's James Griffiths in Colombo

Facebook and WhatsApp are still blocked in Sri Lanka, days after the Easter Sunday terrorist attacks.

Many Sri Lankans are turning to VPNs to get around the ban, with a massive uptick in searches for VPNs and information on how to get around the blocks, according to Simon Migliano, head of research at Top10VPN.com.

The problem is that for most Sri Lankans, Facebook is the internet and how friends and family communicate. Given how integral the social network is to their daily lives, it’s to be expected that Sri Lankans are finding ways around the shutdown, such as by using Virtual Private Networks (VPN).What is surprising however is the sheer size of the spike in demand: our global monitoring data shows that over the two days following the attack the daily average number of VPN searches surged by over 12,000% compared to daily searches over the 30 days prior.

Experts and locals have criticized the ban as counterproductive and illiberal, and questioned the government's justification for the ban as preventing the spread of "false information."

"As facts are developing it's becoming clearer that the government of Sri Lanka has a lot to explain owing to its failure in keeping its citizens secure," said Mishi Choudhary, legal director at the Software Freedom Law Center.

"Shutting down social media at such a time when people whose loved ones have died are seeking answers seems selfish and politically motivated," she added.

12:24 a.m. ET, April 24, 2019

Counterintelligence expert: "The first question you have is imminent threat"

Former FBI Senior Intelligence Adviser and CNN contributor Phil Mudd warned on Tuesday that focusing on local group National Tawheed Jamath (NTJ), which has been accused of carrying out the blasts, could leave the country open to another attack.

NTJ has not claimed the attacks. Meanwhile, ISIS did claim responsibility for the bombings last night, but its involvement has not been proven.

"If you have an ISIS claim of responsibility, given ISIS and what they’ve done, in places like Europe, the Middle East and elsewhere, you gotta sit back and take it seriously," he said.

Mudd later added:

If you’re talking about an attack of this magnitude, the first question you have is imminent threat. Are there other people running around with detonators who are going to kill people? You can speculate later on what the motivation is… but right now, focus on the threat, motivation comes later.

Sri Lankan Prime Minister Ranil Wickremesinghe told reporters on Tuesday that there were "still people on the run with explosives."

"Maybe I should have stayed and covered them with my body": Father who lost two teenage kids

The Linsey family Linsey Family Photo

Matt Linsey lost two of his children in the Shangri-La hotel bombing. The London-based investment banker fled the hotel restaurant as the first bomb exploded, shepherding his children Daniel, 19, and Amelie, 15, out of the room.

But a second explosion detonated near the elevators on the third floor of the upmarket hotel, and killed them both.

His face peppered with minute scars from shrapnel and debris, Linsey is tormented by what he could have done differently.

"Maybe I should have stayed and covered them with my body," he told CNN.

"They both were unconscious," he said. "My daughter seemed to be moving. My son wasn't. A woman offered to take my daughter downstairs to the ambulance. I needed help moving my son." Thinking his daughter was in safe hands and less injured, Linsey traveled with his son in the ambulance to the hospital.There he tried to revive his son, unsuccessfully. "I tried to massage his heart," the father said.He tried to find his daughter, he explains, his voice a hoarse whisper of exhaustion. "This was the worst part... because I yelled for help. That's why I've lost my voice." Amid the overflowing hospital, Linsey found a lifeless Amelie under a hospital sheet.

New Zealand and France spearhead efforts to end use of social media for acts of terrorism

New Zealand Prime Minister Jacinda Ardern speaks to the media in Auckland, New Zealand to announce that France and New Zealand will lead global efforts to try to end the use of social media to organise and promote terrorism. Phil Walter/Getty Images

New Zealand and France are convening world leaders and tech giants to end the use of social media platforms for organizing and promoting terror acts. The meeting, co-chaired by New Zealand Prime Minister Jacinda Ardern and French President Emmanuel Macron, will take place in Paris on May 15, the New Zealand government has announced.

The meeting was prompted by the March terror attack on mosques in the New Zealand city of Christchurch, and aims to get tech giants pledge to "eliminate terrorist and violent extremist content online," a statement says.

Social networks were also blocked in Sri Lanka after Sunday's attacks, with the government citing "false reports." Facebook and Whatsapp continued to be unavailable on Wednesday, say CNN staffers on the ground.

Ardern has urged tech companies to get on board with the initiative:

The March 15 terrorist attacks saw social media used in an unprecedented way as a tool to promote an act of terrorism and hate. We are asking for a show of leadership to ensure social media cannot be used again the way it was in the March 15 terrorist attack.We’re calling on the leaders of tech companies to join with us and help achieve our goal of eliminating violent extremism online at the Christchurch Summit in Paris.

11:05 p.m. ET, April 23, 2019

BREAKING: Death toll rises to 359

Sri Lankan police tell CNN the death toll has jumped to 359, up from a previous count of 321 people.

A still from the video released by the Amaq news agency, claiming to show the Sri Lanka bombers ISIS

Early warnings from India's intelligence services to Sri Lankan officials ahead of the Easter Sunday bombings were based on information gleaned from an ISIS suspect, CNN has learned.

Delhi passed on unusually specific intelligence in the weeks and days leading up to the attacks, Sri Lankan officials have said, and at least some of it was gleaned from material obtained during interrogations of an ISIS suspect arrested in India, an Indian official told CNN.

The suspect gave investigators the name of a man he trained in Sri Lanka, who is associated with a local extremist group implicated in the bombings, the source said. The man, Zahran Hashim, was identified in a video of the purported attackers released Tuesday by ISIS, which claimed responsibility for the Easter Sunday killings.

In a statement published by the ISIS-affiliated news agency Amaq, the group said the attackers were "fighters of the Islamic State."

The involvement of a foreign organization would explain how a previously marginal domestic extremist group blamed for the attacks, National Tawheed Jamath (NTJ), could have pulled off one of the worst terrorist atrocities since 9/11.